My son took steroids from 7 - 10 months of age, with a dose of 2 mg/kg, for his parotid hemangioma. The two most difficult aspects were, by far the lack of sleep and the difficulty getting the medicine into him.
On sleeping, after a couple of weeks on the medication, he would not sleep for longer than 1.5 hours at a time - day or night. I have to say that it was awful. Also, he hated the taste of the medicine and so getting it into him was a constant battle - thank god that he was taking a bottle by then but if we put too much formula, he wouldn't drink it all and too little and he wouldn't drink any because of the taste! If we just tried to give it to him straight, he would either spit it out or throw it up.
On the positive side, he wasn't crankier than usual and didn't have any stomach problems (he took Zantac with the steroids). And, best of all, the steroids had a really positive impact on the size of the hemangioma - we couldn't have hoped for better results!
Good luck and I hope it goes well.